Marine engines are used in very different conditions from that of automotive engines. They are also operating at much cooler temperatures as their cooling systems use water from the surrounding environment such as lakes, rivers or sea water. As a result, when running at a full load but at low coolant temperatures, these engines create thick deposits on spark plugs, pistons and ports. This is the reason why dedicated lubricants, specially formulated for Marine applications, are required for your engine to function securely in marine conditions.